Abrasive bristle, method for the manufacture thereof, brush with abrasive bristles and method for the surface treatment of a workpiece with a brush having abrasive bristles

ABSTRACT

For the manufacture of an abrasive bristle, a plastic material is melted, and a granular material made of abrasive particles is mixed into the melt. The melt is extruded together with the abrasive particles into a filament, and the filament is subsequently treated and cut up. The plastic material may be a high-temperature-resistant polymer with a continued use temperature of ≧150° C. and for the melt with the abrasive particles to be extruded at a temperature of ≧280° C. A brush equipped with corresponding abrasive bristles can be used for the surface treatment of a workpiece, whereby the brush is rotated with a speed in the range of 3,000 rpm to 12,000 rpm and is brought into contact with the surface to be treated.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a United States National Phase Application ofInternational Application PCT/EP2013/000140 filed Jan. 18, 2013 andclaims the benefit of priority under 35 U.S.C. §119 of German PatentApplication DE 10 2012 001 623.9 filed Jan. 30, 2012 and German PatentApplication DE 10 2012 009 087.0 filed May 9, 2012, the entire contentsof which are incorporated herein by reference.

FIELD OF THE INVENTION

The invention pertains to a method for the manufacture of an abrasivebristle, wherein a plastic material is melted and a granular materialmade of abrasive particles is mixed into the melt, and wherein the meltwith the abrasive particles is extruded into a filament, and thefilament is subsequently treated and cut up. Further, the presentinvention pertains to a corresponding abrasive bristle.

Furthermore, the present invention pertains to a brush with abrasivebristles and a method for the surface treatment of a workpiece with abrush, which has abrasive bristles or consists of same.

BACKGROUND OF THE INVENTION

Abrasive bristles of the type mentioned are usually used wherever asurface of a workpiece must be treated and in particular be abraded orpolished.

The abrasive bristles are usually manufactured by a plastic material,for example, made of polyamide 6.12 being melted in an extruder.Granular material-type abrasive particles are mixed into the plasticmelt and the melt is extruded together with the abrasive particlesthrough a nozzle and fed in the form of a so-called endless filament tofurther treatment stations, in which the filament can be stretchedand/or heated and/or shrunk. The filament is then cut to a desiredlength for the manufacture of the individual bristles.

It has been shown that such abrasive bristles can perform their abrasivetreatment function only for a relatively short use time. When thebristles are drawn over the workpiece to be treated, for example, in theform of a rotating brush, high forces arise, which reduce the usabilityof the individual bristle.

SUMMARY OF THE INVENTION

The basic object of the present invention is to create an abrasivebristle, which has a long duration of use, and a method for themanufacture of a corresponding abrasive bristle. Furthermore, a brushwith abrasive bristles and a method for the surface treatment of aworkpiece shall be created, with which the workpiece can be treatedquickly and in a cost-effective manner.

This object is accomplished according to the present invention by amethod with a plastic material that is melted and a granular materialmade of abrasive particles that is mixed into the melt. The melt withthe abrasive particles is extruded into a filament, and the filament issubsequently treated and cut up. Here, provisions are made for theplastic material to be a high-temperature-resistant polymer with acontinued use temperature of ≧150° C. and for the melt with the abrasiveparticles to be extruded at a temperature of ≧280° C.

The continued use temperature represents the temperature limit, abovewhich a substantial reduction of the strength properties of the plasticmaterial occurs due to technical stress. The continued use temperature(also called Relative Temperature Index, RTI) is the highesttemperature, at which the material still has at least 50% of itsproperties (tensile strength or resistance to stretching) after a settime interval of usually 20,000 hr. (see also International Standard IEC60216-1).

The present invention is based on the basic idea that the problems withthe previous abrasive bristles were caused by a relatively greatfriction developing between the abrasive bristles and the workpiece whenusing the abrasive bristles, which leads to high temperatures, whichreduces the stability of the abrasive bristles. This is avoided,according to the present invention, by the plastic material, i.e., thematrix of the abrasive bristle, consisting of ahigh-temperature-resistant polymer. The bristles may consist ofpolyketones (e.g., polyether ether ketones (PEEK), polyaryl etherketones (PAEK) or mixtures thereof), polyphenylene sulfide (PPS) or ofalloys of polyarylene sulfide, or polyphenylene sulfide and polyarylether ketone, partially aromatic polyamides such as polyphthalamides(PPA) (e.g., PA 3T, PA 6T or PA 9T, etc., among others), or even ofmixtures or blends of these plastics.

The filaments according to the present invention may be round orn-angular with n ≧3 as well as in the form of a small strip.

In order to achieve a good embedding of the abrasive particles into theplastic material, the melt with the abrasive particles is extruded at atemperature of ≧280° C. In a preferred embodiment of the presentinvention, provisions are made for the melt with the abrasive particlesto be extruded at a temperature of 300° C. to 400° C.

In a variant of the present invention, provisions are made for theplastic material to be partially crystalline. This makes it possible tosubsequently stretch the filament manufactured with the extrusion, suchthat the filament does not tear or is otherwise damaged.

Particles made of SiC and/or of Al₂O₃, for example, can be used asabrasive particles. However, it is also possible to provide diamondchips or particles and/or corundum particles and/or ceramic particlesand/or boron carbide particles as abrasive particles.

In order to improve the adhesion between the plastic material and theabrasive particles, these can be coated with an adhesive before mixinginto the plastic melt. In this connection, a coating with silanes, forexample, is known from the literature.

The abrasive particles can be inserted into the melted plastic materialand brought together with same to the extrusion temperature of ≧280° C.As an alternative, however, it is also possible at first to bring theplastic material to a temperature of ≧280° C. and thereby melt theplastic material and only then mix the abrasive particles into the melt.

With regard to the abrasive bristle, the above-mentioned object isaccomplished by an abrasive bristle with abrasive particles that consistof SiC and/or Al₂O₃ and/or are formed by diamond particles and/orcorundum particles and/or ceramic particles and/or boron carbideparticles and/or zirconium oxide. Provisions are made for the plasticmaterial to be a high-temperature-resistant plastic material.

Further features of the abrasive bristle according to the presentinvention as well as the advantages given therewith are alreadymentioned in connection with the method according to the presentinvention, to which reference is made for the purpose of avoidingrepetitions.

The abrasive bristles according to the present invention are used forthe surface treatment of a workpiece, in particular in a brush, whichhas a bristle carrier, which carries a bristle filling, whereby thebristle filling has abrasive bristles or abrasive bristles manufacturedaccording to a process that includes melting a plastic material andmixing a granular material made of abrasive particles into the melt,wherein the melt with the abrasive particles is extruded into afilament, and the filament is subsequently treated and cut up, whereinthe plastic material is a high-temperature-resistant polymer with acontinued use temperature of ≧150° C., and the melt with the abrasiveparticles is extruded at a temperature of ≧280° C. The melt with theabrasive particles may be extruded at a temperature of 300° C. to 400°C. The abrasive particles may be mixed into the melt at a temperature of≧280° C. The abrasive bristles are made of a plastic material, intowhich abrasive particles are mixed, wherein the plastic material is ahigh-temperature-resistant material with a continued use temperature of≧150° C. The plastic material may be partially crystalline. The abrasiveparticles may consist of SiC and/or Al₂O₃ and/or are formed by diamondparticles and/or corundum particles and/or ceramic particles and/orboron carbide particles and/or zirconium oxide. The abrasive particlesmay be coated with an adhesive. Preferably, the bristle filling consistsentirely of corresponding abrasive bristles.

With a corresponding brush, a material abrasion on the surface of theworkpiece and thus its fast treatment can be achieved without therebeing a risk that forces developing during the treatment and especiallytemperatures lead to a compromise of the functionality of the abrasivebristles and thus of the brush.

According to a method according to the present invention for the surfacetreatment of a workpiece by means of a brush, which has abrasivebristles made of a plastic material, into which abrasive particles aremixed, with the plastic material being a high-temperature-resistantmaterial with a continued use temperature of ≧150° C. or abrasivebristles manufactured according to the method that includes melting aplastic material and mixing a granular material made of abrasiveparticles into the melt, wherein the melt with the abrasive particles isextruded into a filament, and the filament is subsequently treated andcut up, and the plastic material is a high-temperature-resistant polymerwith a continued use temperature of ≧150° C., and the melt with theabrasive particles is extruded at a temperature of ≧280° C. The brush isrotated and brought into contact with the surface to be treated. Thebrush here has a speed of 3,000 rpm to 12,000 rpm and in particular aspeed of 5,000 rpm to 9,000 rpm. These very high rotation speeds of thebrush lead to a very high material abrasion and to the fast treatment ofthe workpiece. The relatively high temperatures occurring here may bewithstood by the abrasive bristles according to the present inventionwithout compromising the mode of action.

Preferably, the size of the brush and in particular the length of thebristles are designed such that the bristle ends are moved with aperipheral speed of 5,000 m/min to 7,000 m/min.

The method is particularly effective when the bristle filling of thebrush being used in the method consists entirely of abrasive bristlesmade of a plastic material, into which abrasive particles are mixed, andthe plastic material is a high-temperature-resistant material with acontinued use temperature of ≧150° C. or of abrasive bristles, which aremanufactured according to the method that includes melting a plasticmaterial and mixing a granular material made of abrasive particles themelt, wherein the melt with the abrasive particles is extruded into afilament, and the filament is subsequently treated and cut up, and theplastic material is a high-temperature-resistant polymer with acontinued use temperature of ≧150° C., and the melt with the abrasiveparticles is extruded at a temperature of ≧280° C.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this disclosure. For a better understanding of the invention,its operating advantages and specific objects attained by its uses,reference is made to the accompanying drawings and descriptive matter inwhich preferred embodiments of the invention are illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a diagrammatic view of a flow chart showing the steps of amethod of the present invention;

FIG. 2 is a side view of an apparatus for forming a filament of thepresent invention;

FIG. 3 is a side view of a bristle carrier of the present invention; and

FIG. 4 is a perspective view of a brush of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a flow chart showing the steps of a method of the presentinvention. A plastic material is melted in step 1. In step 3, a granularmaterial is mixed into the melted plastic material. In anotherembodiment, the plastic material can be melted and the granular materialcan be mixed with the plastic material at the same time. The meltedplastic material with the abrasive particles is extruded into a filamentin step 5. The filament is treated and cut in step 7. In anotherembodiment, it is possible to cut the filament in one step and thentreat the filament in another step. In yet another embodiment, thefilament can be treated in one step and then cut in another step.

FIG. 2 is a side view of an apparatus for forming a filament 13. A mixer9 receives a melted plastic material and abrasive particles. Theabrasive particles may be coated with an adhesive. The melted plasticmaterial and the abrasive particles are mixed in the mixer 9. Anextruder 11 receives the melted plastic material with the abrasiveparticles. The extruder 11 forms the filament 13. The melted plasticmaterial with the abrasive particles are extruded at a temperaturegreater or equal to than 280° C., preferably at a temperature of 300° C.to 400° C. A cutting and treating structure 15 is provided to cut andtreat the filament 13. In another embodiment, the extruder 11 mayreceive the melted plastic material separately from the abrasiveparticles such that the extruder 11 mixes the melted plastic materialwith the abrasive particles. In another embodiment, a device may beprovided for cutting the filament that is separate from a device thattreats the filament.

FIG. 3 is a side view of a bristle carrier 17. The bristle carrier 17carries a bristle filling 19. The bristle filling 19 has abrasivebristles 21. The abrasive bristles 21 include a plastic material andabrasive particles with the plastic material having ahigh-temperature-resistant material with a continued use temperaturethat is greater than or equal to 150° C.

FIG. 4 is a perspective view of a brush 23. The abrasive bristles 21 areconnected to the brush 23. In one embodiment, the abrasive bristles 21are connected directly to the brush 23. In another embodiment, theabrasive bristles 21 are connected to the brush 23 via the bristlecarrier 17 of FIG. 3. The brush 23 may be rotated, such as by a motor,at a speed of 3,000 rpm to 12,000 rpm, preferably in a range of 5,000rpm to 9,000 rpm. Ends of the bristles may be moved with a peripheralspeed of 5,000 m/min to 7,000 m/min.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

1. A method for manufacture of an abrasive bristle, the methodcomprising: melting a plastic material and mixing a granular materialmade of abrasive particles into the melt; extruding the melt with theabrasive particles into a filament; and treating and cutting thefilament, the plastic material comprising a high-temperature-resistantpolymer with a continued use temperature greater than or equal to 150°C., and the melt with the abrasive particles being extruded at atemperature greater than or equal to 280° C.
 2. A method in accordancewith claim 1, wherein the melt with the abrasive particles is extrudedat a temperature of 300° C. to 400° C.
 3. A method in accordance withclaim 1, wherein the plastic material is partially crystalline.
 4. Amethod in accordance with claim 1, wherein the abrasive particlescomprise SiC and/or Al₂O₃ and/or are formed by diamond particles and/orcorundum particles and/or ceramic particles and/or boron carbideparticles and/or zirconium oxide.
 5. A method in accordance with claim1, wherein the abrasive particles are coated with an adhesive.
 6. Amethod in accordance with claim 1, wherein the abrasive particles aremixed into the melt at a temperature greater than or equal to 280° C. 7.An abrasive bristle, comprising: a plastic material, into which abrasiveparticles are mixed, said plastic material comprising ahigh-temperature-resistant material with a continued use temperaturegreater than or equal to 150° C.
 8. An abrasive bristle in accordancewith claim 7, wherein the plastic material is partially crystalline. 9.An abrasive bristle in accordance with claim 7, wherein the abrasiveparticles comprise SiC and/or Al₂O₃ and/or are formed by diamondparticles and/or corundum particles and/or ceramic particles and/orboron carbide particles and/or zirconium oxide.
 10. An abrasive bristlein accordance with claim 7, wherein the abrasive particles are coatedwith an adhesive.
 11. A brush for a surface treatment of a workpiece,the brush comprising: a bristle carrier, which carries a bristlefilling, whereby the bristle filling has one of bristle filling abrasivebristles and manufactured abrasive bristles, said bristle fillingabrasive brittles comprising a bristle filling plastic material, intowhich bristle filling abrasive particles are mixed, said bristle fillingplastic material comprising a high-temperature-resistant material with acontinued use temperature greater than or equal to 150° C., saidmanufactured abrasive bristles being manufactured according to a method,said method comprising melting a manufactured abrasive bristles plasticmaterial and mixing a granular material made of manufactured abrasivebristles abrasive particles into the melt, extruding the melt with themanufactured abrasive bristles abrasive particles into a filament at atemperature greater than or equal to 280° C., and treating and cuttingthe filament, the manufactured abrasive bristles plastic materialcomprising a high-temperature-resistant polymer with a continued usetemperature greater than or equal to 150° C.
 12. A brush in accordancewith claim 11, wherein the bristle filling consists entirely of said oneof said bristle filling abrasive bristles and said manufactured abrasivebristles.
 13. A method for a surface treatment of a workpiece, themethod comprising: providing a brush, which has one of brush abrasivebristles and manufactured brush abrasive bristles, said brush abrasivebristles comprising a brush abrasive bristles plastic material and brushabrasive particles, said brush abrasive bristles plastic materialcomprising a brush abrasive bristles high-temperature-resistant materialwith a continued use temperature greater than or equal to 150° C., saidmanufactured brush abrasive bristles being manufactured via amanufacturing method, said manufacturing method comprising melting amanufactured plastic material and mixing a granular material made ofmanufactured abrasive particles into the manufactured plastic materialmelt, extruding the melt with the manufactured abrasive particles into afilament at a temperature greater than or equal to 280° C., and treatingand cutting the filament, wherein the manufactured plastic materialcomprises a manufactured high-temperature-resistant polymer with acontinued use temperature greater than or equal to 150° C., rotating thebrush and bringing the brush into contact with the surface to betreated, wherein the brush is rotated with a speed of 3,000 rpm to12,000 rpm.
 14. A method in accordance with claim 13, wherein the brushis rotated with a speed in a range of 5,000 rpm to 9,000 rpm.
 15. Amethod in accordance with claim 13, wherein ends of the bristles aremoved with a peripheral speed of 5,000 m/min to 7,000 m/min.
 16. Amethod in accordance with claim 13, wherein the bristle filling of thebrush consists entirely of said one of said brush abrasive bristles andsaid manufactured abrasive bristles.